content: /*
   * Copyright 2017 David Karnok
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package hu.akarnokd.reactive4javaflow.impl.operators;
  
  import hu.akarnokd.reactive4javaflow.*;
  import hu.akarnokd.reactive4javaflow.fused.ConditionalSubscriber;
  
  import java.util.concurrent.*;
  
  public final class FolyamThrottleFirstTime<T> extends Folyam<T> {
  
      final Folyam<T> source;
  
      final long time;
  
      final TimeUnit unit;
  
      final SchedulerService executor;
  
      public FolyamThrottleFirstTime(Folyam<T> source, long time, TimeUnit unit, SchedulerService executor) {
          this.source = source;
          this.time = time;
          this.unit = unit;
          this.executor = executor;
      }
  
      @Override
      protected void subscribeActual(FolyamSubscriber<? super T> s) {
          if (s instanceof ConditionalSubscriber) {
              source.subscribe(new ThrottleFirstTimeConditionalSubscriber<>((ConditionalSubscriber<? super T>)s, time, unit, executor));
          } else {
              source.subscribe(new ThrottleFirstTimeSubscriber<>(s, time, unit, executor));
          }
      }
  
      static final class ThrottleFirstTimeSubscriber<T> implements ConditionalSubscriber<T>, Flow.Subscription {
  
          final FolyamSubscriber<? super T> actual;
  
          final long time;
  
          final TimeUnit unit;
  
          final SchedulerService executor;
  
          long lastTime;
  
          Flow.Subscription upstream;
  
          ThrottleFirstTimeSubscriber(FolyamSubscriber<? super T> actual, long time, TimeUnit unit, SchedulerService executor) {
              this.actual = actual;
              this.lastTime = Long.MIN_VALUE;
              this.time = time;
              this.unit = unit;
              this.executor = executor;
          }
  
          @Override
          public void onSubscribe(Flow.Subscription subscription) {
              upstream = subscription;
              actual.onSubscribe(this);
          }
  
          @Override
          public void onNext(T item) {
              if (!tryOnNext(item)) {
                  upstream.request(1);
              }
          }
  
          @Override
          public boolean tryOnNext(T item) {
              long now = executor.now(unit);
              if (lastTime + time <= now) {
                  lastTime = now;
                  actual.onNext(item);
                  return true;
              }
              return false;
          }
  
          @Override
          public void onError(Throwable throwable) {
              actual.onError(throwable);
          }
  
          @Override
          public void onComplete() {
              actual.onComplete();
          }
  
          @Override
          public void request(long n) {
              upstream.request(n);
          }
  
          @Override
          public void cancel() {
              upstream.cancel();
          }
      }
  
  
      static final class ThrottleFirstTimeConditionalSubscriber<T> implements ConditionalSubscriber<T>, Flow.Subscription {
  
          final ConditionalSubscriber<? super T> actual;
  
          final long time;
  
          final TimeUnit unit;
  
          final SchedulerService executor;
  
          long lastTime;
  
          Flow.Subscription upstream;
  
          ThrottleFirstTimeConditionalSubscriber(ConditionalSubscriber<? super T> actual, long time, TimeUnit unit, SchedulerService executor) {
              this.actual = actual;
              this.lastTime = Long.MIN_VALUE;
              this.time = time;
              this.unit = unit;
              this.executor = executor;
          }
  
          @Override
          public void onSubscribe(Flow.Subscription subscription) {
              upstream = subscription;
              actual.onSubscribe(this);
          }
  
          @Override
          public void onNext(T item) {
              if (!tryOnNext(item)) {
                  upstream.request(1);
              }
          }
  
          @Override
          public boolean tryOnNext(T item) {
              long now = executor.now(unit);
              if (lastTime + time <= now) {
                  lastTime = now;
                  return actual.tryOnNext(item);
              }
              return false;
          }
  
          @Override
          public void onError(Throwable throwable) {
              actual.onError(throwable);
          }
  
          @Override
          public void onComplete() {
              actual.onComplete();
          }
  
          @Override
          public void request(long n) {
              upstream.request(n);
          }
  
          @Override
          public void cancel() {
              upstream.cancel();
          }
      }
  }
  